Hydrogenation of polymers having ketone groups

Abstract

Polymers containing ketone groups such hydroesterified 1,3-butadiene polymers, including styrenic block copolymers, are hydrogenated with a cobalt/aluminum catalyst which substantially converts ketone groups to alcohol groups and improves polymer stability.

What is claimed is: 
     
       1. A polymer comprising polymerized 1,3-butadiene units and both carboxylic ester groups and alcohol linking groups, the ester groups being pendent from backbone carbon atoms and the alcohol linking groups having the following structure ##STR10## which connects two backbone carbon atoms. 
     
     
       2. The polymer of claim 1 wherein the polymerized 1,3-butadiene units are present as at least one butadiene block in a block copolymer that contains at least one monoalkenylarene block. 
     
     
       3. The polymer of claim 2 wherein the monoalkenylarene block predominently comprises polystyrene. 
     
     
       4. A polymer comprising polymerized 1,3-butadiene units and both carboxylic ester groups and alcohol linking groups, the ester groups being pendent from backbone carbon atoms and the alcohol linking groups having the structure   --CH(CH.sub.3)--CH(OH)--     which connects two backbone carbon atoms, wherein the ester groups include either of the following structures ##STR11## wherein R represents a hydrocarbon group having 1 to 20 carbon atoms, and wherein the polymer does not contain ketone groups when analyzed by an infrared method.   
     
     
       5. The polymer of claim 4 wherein R is a methyl group.